Sudden deaths with kaiseri

I have seen my my kaiseri all die off in the last 2 months with little or no explination, i recieved 5 lovely specimens from Martin Davies last march and 2 from salamanderland and subsequently ,they have all died off unexplainably I have just checked on my last 2 remaining to find 1 of them is in the water bowl and 1 stone dead with no sores,or obvious injuries also the one's that have died have had substantial weight.I can't understand what may have gone wrong their enclosure is clean,they are well fed ,the temperatures are not extreme. I was keeping them in a 50/50 setup recently and they were aquatic for around 2 or 3 weeks then they came back on land ( i had 2 left at this point) I laced them back in a terrestrial setup with damp areas and there skin seemed to have a shiny appearance in patches,they havent come into contact with anyother species,and all my other newts are healthy. I have been feeding them crickets as i have for the last year and there are woodlice in their enclosure along with cocohusk and corkbark.I seem to have one left ,but he doesnt look to promising,The dead one is as stiif as a board the 2 of them were both in clear view in the terrarium during the day,which i thought was strange but i thought they had gotten bolder after being aquatic,has anyone got any ideas?

What size we're they? Can you describe their enclosure?

I raised a good number of kaiseri last year and found that smaller newts in the group were more sensitive to moisture levels than their larger siblings. Weaker newts benefitted from being kept in a wet towel enclosure. In a regular soil setup they struggled to remain hydrated. Fortunately I only lost one before I figured out what they needed. I only mention this because you said one was in the water bowl.

Thanks for your response Mark,The kaiseri i had were Cb 2010 so of substantial size the ones from ,Martin were lovely robust healthy animals and the ones from salamanderland were really small skinny creatures ,I kept Martins ones quite healthy for the last year ,they eat,hunt,very skittish to start with then quite bold and almost doubled in size they were healthy and robust newts.I lost 1 last summer,which i thought i may have squished accidentally,2 died within 6 months for no apparent reason( i believed it to be from crickets) although im not sure.Ive kept them terrestrial up untill 6 to 8 weeks ago then kept them semi terrestrial .two to 3 entered the water and stayed there for a week or so then alternated between land and water ,then the salamanderland 2 stopped eating and got skinnier than they were to start with.Then all were out in the open during the day,without hiding ,which i thought was them getting bold /breeding conditioning etc.then the 2 salland were that skinn i moved them to an enclosure with springtails whiteworms etc.They died overnight.that wouldve been a month ago .Then there were 2 one which i believed to be a gravid female.She left the water,as did the other.Then i would find them climbng the glass so i moved them at last weekend to a terrestrial large tub with a large slate,dry cocohusk,wet cocohusk,waterbowl,lots of cork hides/plant pots(unused).i checked them yesterday and the largest seemed ok but had damp patches on their skin . il eft them alone one is burrowing in to the waterhole and the other 1 buried itself into the corner of the tub and earlier this eve was rigamortis

I have no idea. The deaths could all be unrelated. I think swapping between aquatic and terrestrial phase sometimes is problematic for sub adult kaiseri. I always allow them to decide when they want to leave the water rather than forcing them. I provide a large floating piece of polystyrene with moss and hides on it. There could also be some nutritional issues. I rarely feed mine crickets, they live on a staple of earthworms with the occasional waxworm or mealworm thrown in.

Personally if I were you I would "hospitalise" the remaining newt in a small tub lined with damp paper towels, ventilated secure lid and a dark cork hide. Feed it earthworms if you can.

I also had sudden deaths in my kaiseri. They were all entirely aquatic (by choice; they had the option of climbing onto rocks and burrowing into a coconut fibre area), and I lost 3 of them over the winter, during some freezing but not particularly severe weather, and I lost the last one recently. One day they'd look perfectly healthy, the next they'd be dead.